As disclosed in Patent Document 1 (U.S. Pat. No. 4,941,796), a water conduit is formed at the rear upper portion of a toilet main unit to spout flush water supplied from a storage tank into a bowl portion, and a rim portion is formed along the top edge portion of the bowl portion over this water conduit. In this rim portion, an inner edge portion formed on the inside of the toilet main unit, and an outside edge portion formed on the outside of the toilet main unit are formed in essentially the same angular shape.